The present invention relates to the monitoring of the flow of a medium along the blade path of a turbine.
Turbine blading is constructed to be subjected to a flow of propelling medium, which may be steam or gas, having a flow rate which can reach a maximum design value. If the flow rate of the propelling medium should exceed such maximum value, blade damage can result. Various abnormal operating conditions may cause the flow rate to exceed its maximum design value, such abnormal operating conditions including operation of the turbine with feedwater heaters out of service. The possibility of damage due to the maximum design flow rate being exceeded is particularly great in the case of low pressure turbine exhaust end blading.
In order to prevent the establishment of a flow rate which can cause blade damage, it is currently the practice to provide operators with special operating instructions and/or precautionary instructions. However, there is presently no instrumentation offered to alert operators that the design flow rate is being exceeded.